Another 8.33 kHz Scanner table anybody? Here you are!

[Edelweiss]

Original is in Open Document Spreadsheet Format (which is not permitted here). PM me if you want it, newer Excel will probably open it correctly.

 

[AM909]

I don't know if that doc is for a particular radio/scanner, but the EU's 8.33kHz Voice Channel Spacing (VCS) Implementation Handbook, Annex C (p. 89) has a difference. The original 25-kHz channels may be selected by dialing either that channel (missing from the table posted above) or 5 kHz higher. E.g., dialing either 118.025 or 118.030 on the radio puts it on 118.025 MHz. The rules are, for each "old" 25 kHz channel f:

• dial either f or f+0.005 to get frequency f MHz;
• dial f+0.010 to get frequency f+0.0083 MHz;
• dial f+0.015 to get frequency f+0.0167 MHz.

Note that the dial values f+0.020 are not used (maybe leaving room for further expansion). This ICOM A-220 manual (p. 28) shows the same.

There is also mention of VDL Mode 3 channels, which may be abandoned/stale by my recollection. For each "old" 25 kHz channel f = mmm.hdd MHz:

• if dd is 00 or 50, dial f+0.001, f+0.002, f+0.003, or f+0.004 for frequency f timeslot A, B, C, or D respectively;
• if dd is 25 or 75, dial f-0.004, f-0.003, f-0.002, or f-0.001 for frequency f timeslot A, B, C, or D respectively.

E.g. dial 118.103 for 118.100 MHz timeslot C, dial 118.173 for 118.175 MHz timeslot C, dial 118.751 for 118.750 MHz timeslot A, etc..

 

[Edelweiss]

Well, the EU's table shows both, the 25 channel grid and the 8.33 kHz grid. I have not found a need for the separate old channels listings as I have never heard a controller say tune to 118.0, they will always say 118.005. So IMO the table does the job. I can add that but can't really see the point.

Don't know much about VDL Mode 3 but Wikipedia says it was abandoned. Thank god.

 

[Scan125]

Not wanting to confuse things but I had to work my way through this especially for the Uniden (U)BC125 scanners which get the 8.33 steps wrong. Also my certified Yaesu transceiver was used to verify I was getting it all correct in my software when I had to support Automatic or Prefix Code correction techniques.

Scan125 Control Program User Manual

When I spoke to my brother (retired Senior BA Captain last on 747-400s and DASH-8s, with 20K+ hours and extensive EU short haul experience in the 8.33 zones) about all of this he had a very pragmatic view point. He does not really give a monkeys what actual radiated frequency (except for HF) is used as long as when he sets a given ATC directed value or a published value on pilots airfield information data sheets etc.. What he does care about is that 1) the value as directed is correct, 2) the radio kits does whatever it has to do, and 3) there is someone on the other end

How Uniden got the 125 series scanner 8.33 handling wrong I have no idea as oddly the (U)BC75XLT scanners get things right.

 

[AM909]

...He does not really give a monkeys what actual radiated frequency (except for HF) is used as long as when he sets a given ATC directed value or a published value on pilots airfield information data sheets etc.. What he does care about is that 1) the value as directed is correct, 2) the radio kits does whatever it has to do, and 3) there is someone on the other end

Right; that's the way it's supposed to work.

How Uniden got the 125 series scanner 8.33 handling wrong I have no idea as oddly the (U)BC75XLT scanners get things right.

Because the standard was set with channel numbers that appeared to be frequencies, and were in some cases, making it easy to make that mistake.

Were I involved in setting the standard, I might have argued that using channel numbers that did not resemble the frequency at all might have made even more sense, preventing manufacturers from assuming they were free to use their own scheme, as Uniden apparently did with the 125 series according to your document on the f+0.005 channels for each "old" 25 kHz channel f.

I might have suggested channel numbers n = 10000 + 5 * (f - 118) / 0.0083_ , yielding 10000 for 118.0000 MHz, 10005 for 118.0083 MHz, 10010 for 118.0166 MHz, 10015 for 118.0250 MHz, ..., 20785 for 135.9750 MHz, 20790 for 135.9833 MHz, 20795 for 135.9916 MHz. This gives a consistent 5-digit channel number, with room for future expansion, spacing them by 5.

Or they could have used letter suffixes if they wanted to retain similarity to frequencies but still make it hard for manufacturers to make incorrect assumptions: 11800A for 118.0000 MHz, 11800J for 118.0083 MHz, 11800R for 118.0166, 11802A for 118.0250 MHz, ..., 13597A for 135.9750 MHz, 13597J for 135.9833 MHz, 13597R for 135.9916 MHz, allowing for future expansion and leaving out some letters similar to numbers.

But nobody asked me.